EP-A-0 876 963 describes a stackable and collapsible transport box wherein the side walls can be flipped inwardly about flexible pivots. A rotatable flap, which is rotatable about a horizontal axle, is provided in one of the side walls. The rotatable flap is rotatably connected to the side wall via an insert part which is fastened to a respective indent in the side wall. The floor of the transport box is connected at its corners and in the middle region to vertical supporting pillars which are fastened to a quadrangle supporting frame. The supporting frame has an integral configuration and a massive design.
To ensure that the supporting frame is sufficiently and mechanically stable and that it is able to reliably withstand loads in excess of 1000 kg, the supporting frame needs to have a certain thickness and width. For a transport box having the dimensions of more than 1 meter by 1 meter, the production of such a stable supporting frame will require especially large matrixes. Moreover, such a supporting frame needs to be welded to the supporting pillars or glued to the pillars using an artificial resin glue of very high strength.
Another stackable and collapsible transport box is described in U.S. Pat. No. 4,674,647. This transport box is provided with a pallet-type floor part, two mutually opposite side walls each having a lower hinge, and two other side walls each having a higher hinge. The height of the two side walls having the higher hinges is half the width of the floor part, so that the side walls may lie next to one another in the collapsed state. The maximum height of this transport box is thus limited to half the width of the floor part. Accordingly, this type of transport box can not be efficiently stacked on top of one another.
It is therefore the object of the present invention to provide a stackable and collapsible transport box which is capable of, in the collapsed state, carrying a similarly erected transport box having a load of 1000 kg and more.